1. Field of the Invention
The present invention relates to a Patrone including a spool that winds up film in the form of a roll and a Patrone body for storing the spool so that the spool can rotate freely about the axis thereof.
2. Description of the Related Art
In recent years, proposals have been made for a camera employing a Patrone that enables automatic film feed. After the Patrone is mounted, when a spool axis is rotated, a leader formed in the distal part of film can be fed to a film-wind spool. A variety of proposals have also been made for the structure of the Patrone, especially, for the structure of a shading structure.
A camera in which a magnetic recording means is incorporated has been put to use. A camera that makes it possible to record photographic information or information of processing to be done at a processing laboratory in a magnetic recording section of film has also been proposed. Numerous proposals have been made for a Patrone having a magnetic recording section.
When it comes to the shading structure for a Patrone, a Patrone for photographic film proposed in Japanese Patent Laid-Open No. 4-3153 has an elastic shading plate at a film outlet and thus reduces the resistance against film feed. This art also provides a shading capability that proves effective for film rewind.
The Patrone for photographic film disclosed in Japanese Patent Laid-Open No. 4-3153 has a drawback that when the adhesion of an elastic member improves, the resistance against film passage increases.
A film cartridge for photographic film disclosed in Japanese Patent Laid-Open No. 4-67034 has a structure for intercepting external light by narrowing a space inside the inner wall of a film path, to which a plush is attached at a film outlet, from outside the film path.
In the film cartridge for photographic film disclosed in Japanese Patent Laid-Open No. 4-67034, however, plushes must be overlapped in order to realize reliable shading using plushes. This leads to higher resistance against film passage.
In a film cartridge disclosed in Japanese Patent Laid-Open No. 3-116136, a rotatable shading member is installed independently at a film outlet. No resistance arises against film loading. When stored, the film is shielded from light reliably.
In the film cartridge disclosed in Japanese Patent Laid-Open No. 3-116136, the mechanisms of a rotary member and a rotation drive member are complex. This results in an increase in costs.
Various proposals have been made for the structure of a Patrone that is preferred for a new film format and enables auto-loading of film with ease. For example, a structure disclosed in Japanese Patent Laid-Open No. 3-180837 relates to a Patrone of a film-feed type. As for the Patrone of this proposal, a variety of Improvements for simplifying automatic film feed have been implemented in the shape of the Patrone. The Patrone itself is shaped conveniently for manufacturing by plastic molding, which is lower in cost than a conventional Patrone made of metal.
When film has a magnetic recording section, there is a possibility that magnetic information recorded in the film may be deleted accidentally by a strong external magnetic field induced in, for example, a magnet. A measure must therefore be taken against accidental deletion of magnetic information. In the Patrone of an automatic feed type disclosed in the Japanese Patent Laid-Open No. 3-180837, however, the Patrone itself is adroitly shaped so that film will be fed smoothly by auto-loading. The shape makes manufacturing difficult unless plastic molding is employed.
If a Patrone having the above shape is manufactured using a metal, costs increase. If downsizing is attempted, the number of parts increases.
When a non-magnetic material such as plastic is employed as mentioned above to manufacture a film storage for the film having a magnetic recording section, the magnetic recording section cannot be protected from an external magnetism.
An auto-feed type Patrone has a problem that since the distal part of film itself is relatively soft, it is hard to feed the distal part of film through plushes at an outlet of the Patrone.
In not only the auto-feed type but also an auto-loading type for hooking perforations of film, if a distal part of film has poor strength, perforations are likely to break away.